The invention relates to the field of improving and increasing the flow of fluids, especially water, and especially as applied to propelling water craft.
Various facilities require moving large quantities of fluids as efficiently as possible. Such facilities include waste water treatment plants, cooling towers, and large aquariums in which aeration takes place. In addition, the efficient movement of large quantities of water is necessary for the propulsion of all types of water craft, including large and small ships, pleasure craft and jet skis.
Marine propulsion is generally accomplished either by means of a propeller driven by an engine, or by means of a jet of water produced by a pump and expelled through a nozzle. Conventional propellers are especially troublesome, as they cause cavitation at high speeds and cannot drive a ship at speeds above about 30 knots. In cavitation, the pressure on forward surfaces becomes so low that the water xe2x80x9cboilsxe2x80x9d and creates damaging vibrations.
In U.S. application Ser. No. 09/007,108 filed Jan. 14, 1998, and incorporated herein by reference, Applicant proposed a gas flow director for more efficiently moving gas in order to reduce pressure in a chamber.
In order to reduce the pressure in a chamber, it is well known to use a fan, compressor or other type of gas movement device to blow the gas in the chamber outwardly. The efficiency of such a device lasts only so long as there is gas in the chamber to be evacuated, since the gas assists in turning the fan blades, and reduces the amount of electrical power which must be used to operate the fan. When the pressure in the chamber has been reduced, there is less gas being moved to turn the fan blades, so more electrical power must be applied to the fan to move the blades. The reduction in efficiency at reduced pressures is considerable, and requires the use of a fan sized to be effective at reduced pressure.
The gas flow director proposed in U.S. application Ser. No. 09/007,108 included a pair of corresponding truncated cones, an inner cone and an outer cone defining a space therebetween, with a gas inlet at the larger end of the apparatus and a gas outlet at the smaller end of the apparatus defining a gas flow path through the apparatus. The outer cone has a series of secondary gas inlets at the larger end, and the inner cone is perforated over its surface. The secondary flow of gas through the secondary inlets and the perforations, was found to greatly improve the efficiency of the primary flow of gas.
However, it is also desirable to improve the flow of fluids, in general, and liquids in particular, for numerous application, including propulsion and aeration.
It is therefore an object of the invention to utilize the apparatus as disclosed in U.S. application Ser. No. 09/007,108 for moving fluids, and in particular liquids and liquid-gas mixtures.
It is a further object of the invention to utilize this apparatus in a liquid flow circuit for purposes of marine propulsion.
It is another object of the invention to utilize this apparatus for aeration of liquids.
It is another object of the invention to increase the thrust of a rocket or jet propulsive device by inducing an additional mass of gases into the exhaust stream of the device.
It is another object of the invention to increase the thrust of a rocket or jet propulsive device by reducing the pressure of gases at the exhaust outlet of the device.
These and other objects of the invention are achieved with an apparatus for improving fluid flow, and which comprises an outer shell having an inlet end which is generally closed with a centrally located inlet, a solid truncated side wall, and an outlet end with an outlet therein. Within the outer shell is an inner truncated cone having a larger inlet end generally parallel to the inlet end of the outer shell and side walls, define a space between the side walls of the inner cone and the outer shell. An inlet in the smaller end of the inner cone corresponds to the inlet in the outer cone. The inlet and the outlet define a fluid flow passage through the inner cone. The end and side walls of the inner truncated cone are perforated to permit flow therethrough, the perforations providing a passage between the shells and the fluid flow passage. The inner cone has an outlet corresponding to the outlet of the outer shell.
A plurality of secondary inlets open to the environment are placed in the side wall or the end wall of the outer shell, or in both the side wall and the end wall. These inlets may themselves be in the form of truncated cones, with the smaller ends of these cones passing into the side wall of the outer shell.
The inner truncated cone may have any conical shape between 1 and 89xc2x0, but is preferably about 15 to 75xc2x0.
The outer shell is frequently in the form of a truncated cone corresponding to the inner truncated cone. The outer shell can also have other cross-sections, for example, cylindrical or rectangular.
In operation, a device for moving a fluid, for example a propeller, a pump or a compressor, is used to supply a fluid which will be referred to as a working fluid to the inlet; the working fluid may be a liquid or a gas or a combination thereof. The secondary inlet is supplied with an ambient or compressed gas or a liquid, or combination thereof, which is then induced into the higher pressure flow of the working fluid. In the case of an induced gas, compression of the gas into the working fluid results, creating a homogenized compressed stream liquid/gas at the outlet. The subsequent expulsion of the compressed gas/liquid and the mass flow augmentation due to induction will enhance the thrust of a propulsive system.
While not wishing to be held to a particular explanation, Applicant theorizes that the apparatus incorporates the aerodynamics and fluid dynamics of three-dimensional circulation around a closed path in an irrotational field described by the Law of Biot and Savart. In comparison, an airfoil is a flat or two dimensional application of the Law of Biot and Savart. The operation of the apparatus is thought to be based on the fact that every irrotational flow possesses a velocity potential. The Kutta-Joukowski theorem relates the velocity potential to a force. The apparatus is designed to turn the velocity potential generated force into an impulsive force applied throughout a three-dimensional finite region, the curl of the force having a value at its edge and creating vorticity. This vorticity creates molecular acceleration and turbulence, which thereby creates suction.
The apparatus of the invention has no moving parts, and can withstand high pressures generated by the working fluid. It is not restricted in the volume of gases and liquids which can be induced, but subject only to the volume flow and pressure of the working fluid. In contrast to a venturi, the apparatus of the invention does not depend on narrowing of an area to create an increase in fluid velocity, and thereby a drop in pressure.